1. Field of the Invention
The present invention relates generally to digital cameras, and more particularly to digital camera modules that can be mounted in host electronic devices. Even more particularly, the present invention relates to a process for manufacturing a digital camera module that substantially reduces potential damage to an image capture device during the manufacturing the digital camera or digital camera module.
2. Description of the Background Art
Digital camera modules are currently being incorporated into a variety of electronic devices. Such camera hosting devices include, but are not limited to, cellular telephones, personal digital assistants (PDAs), and computer cams. The demand for digital camera modules continues to grow as the ability to incorporate the camera modules into host devices expands. Therefore, one design goal of digital camera modules is to make them as small as possible so that they will fit into an electronic device without substantially increasing the overall size of the device. Furthermore, it is also desirable to manufacture such digital camera modules as efficiently and robustly as possible. Means for achieving these design goals must, of course, preserve the quality of the image captured by the camera modules.
Typically, digital camera modules include a lens unit, a housing, a circuit substrate, and a solid-state image capture device. Upon assembly, the image capture device is electrically connected to the circuit substrate via a plurality of wire bonds or the like. The circuit substrate is then fixed to the bottom of the housing or the housing is mounted on the circuit substrate. Typically, housings of this type are fabricated (e.g., by injection molding) separately before they are coupled to circuit substrates. After the housing is formed, it is fixed to the circuit substrate by some suitable means such as an adhesive, thermal weld, post/aperture engagement, etc. The lens unit is then adjustably mounted to the opposite end of the housing so that images can be focused onto the image capture device.
The image capture devices are very sensitive, which is a disadvantage in terms of manufacturing time, cost, quality, and yield of the camera module. The image capture device is extremely vulnerable to damage and contamination, particularly before and during the housing attach process. For example, before the housing is attached to the circuit substrate, the wire bonds are exposed to inadvertent contact (e.g., during handling), which can cause damage. Further, the image capture device is vulnerable to contamination from particulate debris caused by the housing attach process. Contamination of the sensor array will block light and cause visible artifacts in every image captured by the device. Obviously, damaged image capture devices causes a decrease in product yield and an increase in labor and material costs.
What is needed therefore, is a method for manufacturing camera modules that reduces the chance of damaging the image capture devices. What is also needed is a method for manufacturing camera modules that results in a higher yield. What is also needed is a method for manufacturing camera modules that results in a faster manufacturing throughput. What is also needed is a less expensive method for manufacturing camera modules.